Causes & Risk Factors
One of the first questions almost every parent asks, often silently, is some version of: did I do something to cause this? I asked it too. So before anything else — for the vast majority of families, there is no single moment or decision that caused it, and this page isn’t about finding one. It’s about understanding, in plain terms, what we currently know about why spastic diplegia happens.
The short version
Spastic diplegia results from atypical development of, or injury to, the parts of the brain that control movement — specifically the pathways connecting the brain’s motor control centers to the spinal cord and legs. This most often happens before birth, during birth, or in the earliest days of life, while the brain is still developing rapidly and is more vulnerable to disruption.
The most well-established risk factor: prematurity
Premature birth — especially very premature birth — and low birth weight are the most consistently documented risk factors for spastic diplegia specifically. A common mechanism is a type of injury to the brain’s white matter (the tissue carrying signals between brain regions) called periventricular leukomalacia, which tends to affect the nerve pathways controlling the legs more than the arms — part of why spastic diplegia so often follows a premature birth.
Other recognized contributors
- Oxygen deprivation around labor and delivery
- Infection during pregnancy, which research has linked to increased risk of brain injury affecting motor development
- Multiple births (twins, triplets) — carry higher risk, partly related to higher rates of prematurity
- Genetic and brain-development factors — in a smaller share of cases, no birth-related event is identified, and the cause relates to how the brain formed rather than an injury during birth
What this page is not
This isn’t a legal or fault-finding page. In most cases, no single preventable error is identifiable, and even where risk factors are present, they describe increased likelihood, not certainty or blame. If you’re looking into whether your child’s diagnosis involved a medical error, that’s a separate, personal decision best made with a qualified attorney reviewing your specific medical records — not something a general information page can or should determine.
Where to go from here